# Monday, January 16, 2017¶

## Worked on the Developer’s Guide¶

I have been working a few hours in the Developer’s Guide. My goal was to collect “everything you need to know about actions” into one place, namely Introduction to actions. I moved quite some docstrings from lino.core.actions to that document.

Yes, it seems that links to lino.core.actions.Action or lino.core.actions.Action.is_window_action() still work. I like this approach. Yes, it seems that complex topics like actions should not rely on autodoc for documenting the API, they should use hand-written prosa documentation. (#1869)

Otherwise, as usual when I have been working on the documentation, I stop working on it because there are so much other things to do and without the feeling of having been efficient.

## A demo tour into Lino Care¶

This weekend I started #1392: write a “quick introductive demo tour” of Lino Care in German. This is theoretically not my job (I usually convince my customers that they must write their end-user documentation themselves).

An important task when writing end-user documentation is collecting screenshots. Hint: Before a screenshot take session I set an exact window size for my browser:

\$ wmctrl -r Firefox -e 0,10,10,800,600


There is some visible result: Schnellkurs Lino Care. As expected, I didn’t get very far with that document. But as a positive surprise to me, I found, without the help of Anna and Johannes, a lot of details to optimize. And of course I fixed them on the spot.

## Pitfall when defining actions with a dialog window¶

I discovered a cool pitfall (by falling into the pit, and it took me more than an hour to understand my mistake).

When you define an action with a dialog window, then you must specify the parameters. And usually you also specify a params_layout. Which usually is a simple multi-line template string:

class MarkVoteRated(VoteAction):
parameters = dict(
rating=Ratings.field(),
comment=dd.RichTextField(_("Comment"), blank=True))
params_layout = dd.Panel("""
rating
comment
""", window_size=(50, 12))


The pitfall is to use ParamsLayout instead of Panel:

class MarkVoteRated(VoteAction):
parameters = dict(
rating=Ratings.field(),
comment=dd.RichTextField(_("Comment"), blank=True))
params_layout = dd.ParamsLayout("""
rating
comment
""", window_size=(50, 12))


In that case, until today, you got no error message, everything seems to work, except that the parameters entered by the user into the dialog window never made it into the action’s code. The action is being executed as if the default values had not been changed.

I added a test to cover this pitfall. As a side effect, Lino is now more severe and requires the developer to be specific when defining detail_layout and insert_layout: I removed dd.FormLayout, we must now use dd.DetailLayout or dd.InsertLayout.